2. Do the chemical reactions featured in the video clip occur in living or non-living systems? Elaborate why.
3. Do chemical reactions occur in the bodies of living things, i.e. plants, animals, micro-organisms? Give your opinions and supporting evidence in the online discussion forum in the workshop wiki.
Activity B: Exploring Chemical Interactions
Steps:
1. You are provided the following materials:
a. a sachet of powdered yeast
b. distilled water
c. one or two sachet(s) of cane sugar (sucrose)
d. a 100ml plastic bottle
e. a small balloon.
2. Add half a teaspoon of the yeast, 40ml water (at room temp) and the packet of cane sugar into the plastic bottle and mix well.
3. Cover the opening of the plastic bottle tightly with a small balloon and observe what happens. (The above activity may take up to 30 minutes for the balloon to inflate.)
4. As the reaction occurs, leave the setup aside. While waiting, brainstorm in groups on the following questions and input your thoughts in the online concept mapping tool software (www.mywebspiration.com):
a. What kind of substance is yeast?
b. What would you expect to see?
c. What do they think is happening between the yeast and sugar solution?
d. How can they modify the setup to test the identity of the gas?
5. Explore chemical changes further with the following questions:
What if…
a. another substance besides sugar is used in this experiment?
b. the temperature of the mixture is changed?
c. the yeast is expired?
d. water is not used in the experiment (i.e. only powdered yeast and sugar are present in the conical flask)?
e. oxygen is missing from the flask? (and any other “what-if” questions you can think of)
Activity C: Presenting thoughts and findings
Steps:
1. In groups on a shared wiki page, present your thoughts on the following questions:
a. Which experiment condition would you like to investigate further?
b. What do you think will happen when you change that condition?
c. How can you conduct an experiment to find out if your prediction is accurate?
d. Which instruments should you use to measure the relevant condition accurately?
e. Which tools can you use to share your results and observations effectively?
2. Conduct a simple poll to select the best experiment design, which will be carried out as a class. You are to evaluate the best experiment based on the following criteria:
a. The variable and hypothesis are clearly stated.
b. The experimental procedures are clear.
c. The experimental procedures change only the intended variable, while keeping all other conditions the same.
d. The experiment used appropriate instruments to record your observations (e.g. stopwatch, data loggers, and spreadsheets).
Activity D: Applications to real life
Description of Activity: Conduct an online research (using a collaborative research tool such as Diigo) on the roles of yeast in alcoholic beverages and bread-making industries, and suggest creative ways of applying your knowledge to real life situations.
Activity E: Summary Activity
Steps:
1. Access the online mind mapping software to summarise your learning.
2. Include the following key words: interactions, chemical reactions, respiration, living things, non-living things, energy. You may include other concepts in the map.
Activity 4: Chemical Changes
Activity A: Discovering Chemical Interactions
Steps:
1. Watch video chip #4, Banging Chemistry: Fast & Furious, which is found at the SciberDiver website:
(http://www.sciberdiver.edu.sg/level.asp?pageCode=SA4DX).
2. Do the chemical reactions featured in the video clip occur in living or non-living systems? Elaborate why.
3. Do chemical reactions occur in the bodies of living things, i.e. plants, animals, micro-organisms? Give your opinions and supporting evidence in the online discussion forum in the workshop wiki.
Activity B: Exploring Chemical Interactions
Steps:
1. You are provided the following materials:
a. a sachet of powdered yeast
b. distilled water
c. one or two sachet(s) of cane sugar (sucrose)
d. a 100ml plastic bottle
e. a small balloon.
2. Add half a teaspoon of the yeast, 40ml water (at room temp) and the packet of cane sugar into the plastic bottle and mix well.
3. Cover the opening of the plastic bottle tightly with a small balloon and observe what happens. (The above activity may take up to 30 minutes for the balloon to inflate.)
4. As the reaction occurs, leave the setup aside. While waiting, brainstorm in groups on the following questions and input your thoughts in the online concept mapping tool software (www.mywebspiration.com):
Share your group map with Egwin_Lian@moe.gov.sg
a. What kind of substance is yeast?
b. What would you expect to see?
c. What do they think is happening between the yeast and sugar solution?
d. How can they modify the setup to test the identity of the gas?
5. Explore chemical changes further with the following questions:
What if…
a. another substance besides sugar is used in this experiment?
b. the temperature of the mixture is changed?
c. the yeast is expired?
d. water is not used in the experiment (i.e. only powdered yeast and sugar are present in the conical flask)?
e. oxygen is missing from the flask?
(and any other “what-if” questions you can think of)
Activity C: Presenting thoughts and findings
Steps:
1. In groups on a shared wiki page, present your thoughts on the following questions:
a. Which experiment condition would you like to investigate further?
b. What do you think will happen when you change that condition?
c. How can you conduct an experiment to find out if your prediction is accurate?
d. Which instruments should you use to measure the relevant condition accurately?
e. Which tools can you use to share your results and observations effectively?
2. Conduct a simple poll to select the best experiment design, which will be carried out as a class. You are to evaluate the best experiment based on the following criteria:
a. The variable and hypothesis are clearly stated.
b. The experimental procedures are clear.
c. The experimental procedures change only the intended variable, while keeping all other conditions the same.
d. The experiment used appropriate instruments to record your observations (e.g. stopwatch, data loggers, and spreadsheets).
Activity D: Applications to real life
Description of Activity:
Conduct an online research (using a collaborative research tool such as Diigo) on the roles of yeast in alcoholic beverages and bread-making industries, and suggest creative ways of applying your knowledge to real life situations.
Activity E: Summary Activity
Steps:
1. Access the online mind mapping software to summarise your learning.
2. Include the following key words: interactions, chemical reactions, respiration, living things, non-living things, energy. You may include other concepts in the map.